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  <title>Document</title>
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<body>
  <script>
    //变量的声明 - let
    let age;//年龄变量

    //变量的赋值 - =
    age = 18;
    //变量的使用
    console.log(age);
    //声明同时直接赋值 - 变量的初始化
    let age1 = 19;

    //更新变量
    age = age1;

    //多变量声明 - 不推荐
    let age2 = 18, uname2 = 'My';
    console(age2, name2);
  </script>
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